An expeditious algebraic formulation to the buckling critical load of risers under dynamic compression

Dynamic compression of risers can play an important role in the structural stability of submerged pipes in catenary-like configuration. In this paper, the analytical formulation for the buckling critical load, developed in the early 2000's, is revisited and extended to cover a wider range of practical cases. A purely algebraic expression for the critical load is provided, eliminating the original formulation requirement related to solving transcendental equations, for both free and anchored risers. The analytic formulations and respective algebraic approximations are compared with numerical simulations, presenting a fairly good agreement. A discussion on the differences and similarities of each formulation ends this paper, highlighting their range of validity. Also, from the comparison, the analytical formulation developed in this work was more suitable for precise and fast determination of the critical buckling load for both riser types, rigid and flexible, and for most typical operating conditions. The proposed algebraic expressions were highly accurate and may substitute the previous analytical formulations for critical load prediction. •Risers may experience buckling due to dynamic compression at small top-end angles.•Prior formulation is improved for an algebraic way to get the buckling critical load.•The buckling critical load can be accurately predicted with just a few parameters.•The algebraic formulation obtains more accurate results, especially in severe cases.•Analytical results confirmed that risers have two mechanisms of load accommodation.